1. Field of the Invention
.sup.123 I has many advantages as a radionuclide for medicinal purposes. The radiation dose resulting from .sup.123 I is much reduced as compared to .sup.131 I or .sup.125 I. For most scanning situations .sup.123 I allows scanning to be accomplished with an acceptable dose. In addition, the gamma radiation emitted is ideal for imaging with scintillation cameras. The relatively short half-life of .sup.123 I allows other radionuclides to be used as well in diagnostic procedures without interference. The radiations resulting from .sup.123 I are readily shielded, so as to decrease radiation hazard to personnel. While the half-life is relatively short, the .sup.123 I half-life is sufficiently long to allow for purification and chemical labeling of compounds, delivery to the clinician, and utilization of the .sup.123 I by the clinician. Finally, .sup.123 I does not have undesirable particulate radiation.
In preparing the .sup.123 I there are a number of significant considerations. Important to the process is the production of .sup.123 I without the concomitant formation of other radionuclides which cannot be conveniently separated from the desired radionuclide and have undesirable properties, for example, particulate radiation. Because the equipment employed for the preparation of radionuclides is expensive and large amounts of energy are utilized, it is desirable that the use of the energy employed be highly efficient as it relates to the yield of the desired radionuclide. Other considerations include the cost of the target material, ease of processing, speed of processing and the like.